The present invention relates to polymers comprising one or more (repeating) unit(s) of the formula *A* and *COM1*, and their use as organic semiconductor in organic devices, especially in organic photovoltaics (solar cells) and photodiodes, or in a device containing a diode and/or an organic field effect transistor. The polymers according to the invention have excellent solubility in organic solvents and excellent film-forming properties. In addition, high efficiency of energy conversion, excellent field-effect mobility, good on/off current ratios and/or excellent stability can be observed, when the polymers according to the invention are used in organic field effect transistors, organic photovoltaics (solar cells) and photodiodes.
U.S. Pat. No. 6,451,459 (EP1078970; cf. B. Tieke et al., Synth. Met. 130 (2002) 115-119; Macromol. Rapid Commun. 21 (4) (2000) 182-189) describes diketopyrrolopyrrole based polymers and copolymers comprising the following units
wherein x is chosen in the range of from 0.005 to 1, preferably from 0.01 to 1, and y from 0.995 to 0, preferably 0.99 to 0, and wherein x+y=1, and    wherein Ar1 and Ar2 independently from each other stand for
    and m, n being numbers from 1 to 10, and    R1 and R2 independently from each other stand for H, C1-C18alkyl, —C(O)O—C1-C18alkyl, perfluoro-C1-C12alkyl, unsubstituted C6-C12aryl or one to three times with C1-C12alkyl, C1-C12alkoxy, or halogen substituted C6-C12aryl, C1-C12alkyl-C6-C12aryl, or C6-C12aryl-C1-C12alkyl,    R3 and R4 preferably stand for hydrogen, C1-C12alkyl, C1-C12alkoxy, unsubstituted C6-C12aryl or one to three times with C1-C12alkyl, C1-C12alkoxy, or halogen substituted C6-C12aryl or perfluoro-C1-C12alkyl, and R5 preferably stands for C1-C12alkyl, C1-C12alkoxy, unsubstituted C6-C12aryl or one to three times with C1-C12alkyl, C1-C12alkoxy, or halogen substituted C6-C12aryl, or perfluoro-C1-C12alkyl, and their use in EL devices. The following polymer
     is explicitly disclosed in Tieke et al., Synth. Met. 130 (2002) 115-119. The following polymers
     are explicitly disclosed in Macromol. Rapid Commun. 21 (4) (2000) 182-189.
M. Smet et al., Tetrahedron Lett. 42 (2001) 6527-6530 describe the preparation of rod-like diketopyrrolopyrrole oligomers by a stepwise sequence of Suzuki couplings using brominated 1,4-dioxo-3,6-diphenylpyrrolo[3,4-c]pyrrole (DPP) derivatives and 1,4-dibromo-2,5-di-n-hexylbenzene as the monomers.
Y. Zhu et al., Macromolecules 40 (2007) 6981-6989 describes five new soluble conjugated polymers, which were prepared upon Suzuki polycondensation reactions. The polymers were prepared from 1,4-diketo-2,5-dihexyl-3,6-bis(4-bromophenyl)pyrrolo[3,4-c]pyrrole (1a), 1,4-diketo-2,5-di-(2-ethylhexyl)-3,6-bis(4-bromophenyl)pyrrolo[3,4-c]pyrrole (1b), or 1,4-diketo-2,5-dihexyl-3,6-bis(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)pyrrolo[3,4-c]pyrrole (1c), and 3,6-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9-ethylhexylcarbazole (2), 4,4′-dibromotriphenylamine (3), 4,4′-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)triphenylamine (4), 2,7-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9,9-dihexylfluorene (5), 9,10-anthracenebispinacolatoboron ester (6), and 4,7-dibromo-2,1,3-benzothiadiazole (7). The polymers exhibit brilliant red colors. Polymer solutions are highly fluorescent with photoemission maxima between 552 and 600 nm.
A. Kuehne et al., Tetrahedron Letters 49 (2008) 4722-4724 discloses the synthesis of the following polymer
by Suzuki coupling. The vinyl ether functionality allows for active incorporation of the light emitting polymers into standard vinyl ether and glycidyl ether photoresist materials.
K. Zhang et al., Makcromolecules 41 (2008) 7287-7295 describes the synthesis and characteristic properties of polymers P-1-P-3 containing the 2,3,5,6-tetraarylated pyrrolo[3,4-c]pyrrole-1,4-dione unit in the main chain. P-1 is prepared from 2,5-bis(4-t-butylphenyl)-3,6-bis(4′-bromophenyl)pyrrolo[3,4-c]pyrrole-1,4-dione (DPP1) and 9,9-di-n-hexylfluorene-2,7′-bispinacolatoboronester 3, P-2 from 2,5-bis(4′-bromo-phenyl)-3,6-bis(4-t-butylphenyl)pyrrolo[3,4-c]pyrrole-1,4-dione (DPP2) and 3, and P-3 from DPP1, 3, and 2,5-bis(n-hexyloxybenzene)-1,4-bispinacolatoboronester 4 via Pd-catalyzed Suzuki coupling. Molecular weights of the polymers are about 8000-10 000 Da.
WO05/049695 discloses diketopyrrolopyrrole (DPP) based polymers and their use in PLEDs, organic integrated circuits (O-ICs), organic field effect transistors (OFETs), organic thin film transistors (OTFTs), organic solar cells (O-SCs), or organic laser diodes, but fails to disclose the specific DPP based polymers of formula I.
A preferred polymer of WO05/049695 comprises a repeating unit of formula
and a repeating unit Ar3, wherein    R1 and R2 are independently of each other a C1-C25alkyl group, especially a C4-C12alkyl group, which can be interrupted by one or more oxygen atoms, and Ar1 and Ar2 are independently of each other a group of formula
wherein —Ar3— is a group of formula
wherein    R6 is hydrogen, C1-C18alkyl, or C1-C18alkoxy, and R32 is methyl, Cl, or OMe, and R8 is H, C1-C18alkyl, or C1-C18alkyl which is substituted by E and/or interrupted by D, especially C1-C18alkyl which is interrupted by —O—.
In another preferred embodiment WO05/049695 is directed to polymers comprising a repeating unit of formula
and a repeating unit Ar3, wherein R1 and R2 are independently of each other a C1-C25alkyl group, especially a C4-C12alkyl group, which can be interrupted by one or more oxygen atoms, and Ar1 and Ar2 are independently of each other a group of formula
especially
wherein R32 is methyl, Cl, or OMe,
and —Ar3— is a group of formula
wherein R6 is hydrogen, C1-C18alkyl, or C1-C18alkoxy, R9 and R10 are independently of each other H, C1-C18alkyl, which can optionally be interrupted by O, or C1-C18alkoxy, which can optionally be interrupted by O,    R9 and R10 together form a group of formula ═CR100R101, wherein    R100 and R101 are independently of each other H, C1-C18alkyl, or    R9 and R10 together form a five or six membered ring, which optionally can be substituted by C1-C18alkyl.
WO08/000,664 describes polymers comprising (repeating) unit(s) of the formula
wherein a, b, c, d, e and f are 0 to 200, especially 0, 1, 2, or 3;
Ar1 and Ar1′ are independently of each other a group of formula

Ar2, Ar2′, Ar3, Ar3′, Ar4 and Ar4′ are independently of each other a group of formula

In a preferred embodiment WO08/000,664 is directed to polymers of formula
wherein A is as defined above and -COM1- is selected from repeating units of formula:
wherein R7 and R7′ are . . . ,    R44 and R41 are hydrogen, C1-C18alkyl, or C1-C18alkoxy, and    R45 is H, C1-C18alkyl, or C1-C18alkyl which is substituted by E and/or interrupted by D, especially C1-C18alkyl which is interrupted by —O—, wherein D and E are as defined above, and -COM2- is a group of formula
wherein    R116 and R117 are independently of each other H, C1-C18alkyl, which can optionally be interrupted by O, or C1-C18alkoxy, which can optionally be interrupted by O,    R119 and R120 are independently of each other H, C1-C18alkyl, which can optionally be interrupted by O, or    R119 and R120 together form a group of formula ═CR100R101, wherein    R100 and R101 are independently of each other H, C1-C18alkyl, or    R119 and R120 together form a five or six membered ring, which optionally can be substituted by C1-C18alkyl.
Martijn M. Wienk et al., Advanced Materials 20 (2008) 2556-2560 relates to narrow-bandgap diketo-pyrrolo-pyrrole polymer solar cells. Photovoltaic devices were made by coating the appropriate pBBTDPP2: fullerene film on patterned indium-oxide-coated glass substrates covered with 60 nm of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). Lithium fluoride (1 nm) and aluminum (100 nm) were used as metal electrode.
pBBTDPP2 is also mentioned in J. Chen et al., Accounts of Chemical Research xx (2009) 1-10 (doi: 10.21/ar90006lz; publication date: 2.07.2009).

Mario Leclerc et al., Macromolecules, 42 (2009) 2891-2894 (online publication date: 26.03.2009; DOI: 10.1021/ma8027003) disclose a poly(2,7-carbazole) derivative (PCBTDPP), namely poly[N-9′-heptadecanyl-2,7-carbazole-alt-3,6-bis(thiophen-5-yl)-2,5-dioctyl-2,5-dihydropyrrolo[3,4-]pyrrole-1,4-dione]. The conjugated polymer exhibits a high hole mobility, optimized HOMO-LUMO energy levels together with good thermal and air stability.
E. Zhou et al., Macromolecules 43 (2010) 821-826 (Online publication date: 28.12.2009; DOI: 10.1021/ma902398q) discloses the synthesis of a highly effective photovoltaic polymer with near-infrared response, poly{N-[1-(2-ethylhexyl)-3-ethylheptanyl]dithieno[3,2-b:2′,3′-d]pyrrole-3,6-dithien-2-yl-2,5-dibutylpyrrolo[3,4-c]pyrrole-1,4-dione-5′,5″-diyl} {P DTPDTDPP(Bu)}. The polymer has high molecular weight, good solubility, and a broad absorption spectrum in the range of 500-1100 nm. Field effect transistor charge mobility of PDTPDTDPP(Bu) arrived 0.05 cm2 V−1 s−1. Bulk heterojunction type polymer solar cells based on PDTPDTDPP(Bu) and PC70BM have broad photocurrent response wavelength range from 300 nm to 1.1 μm.
WO09/047104 relates to small molecule DPP compounds of the formula

wherein . . . Ar1 and Ar4 are independently of each other a bivalent group of the formula
Ar2, Ar3, Ar5, and Ar6 are independently of each other a bivalent group of one of the formulae IV to X and L,

EP2034537A2 discloses polymers of formula
wherein each R is independently selected from hydrogen, an optionally substituted hydrocarbon, and a hetero-containing group; each Ar is independently selected from optionally substituted aryl and heteroaryl groups; each M is an optional, conjugated moiety; a represents a number that is at least 1; b represents a number from 0 to 20; and n represents a number that is at least 1. Among others M can be selected from
and substituted derivatives thereof.
PCT/EP2009/063767 discloses polymers comprising one or more (repeating) unit(s) of the formula
wherein
Ar1, Ar1′, Ar3 and Ar3′ are independently of each other a group of formula
Ar2 is a group of formula

one of X1 and X2 is N and the other is CH, and their use as organic semiconductor in organic devices.
PCT/EP2009/063769 relates to polymers comprising one or more (repeating) unit(s) of the formula
A-D, and at least one (repeating) unit(s) which is selected from repeating units of the formula B-D, A-E, and B-E,
a polymer comprising one or more (repeating) unit(s) of the formula
or
a polymer comprising one or more (repeating) unit(s) of the formula
wherein A is a group of formula

Ar21, Ar21′, Ar31, Ar31′, Ar1 and Ar1′ are independently of each other a group of formula
Ar2, and Ar2′ are independently of each other a group of formula
B, D and E are independently of each other a group of formula
or formula

Ar8 and Ar8′ are independently of each other a group of formula

JP2007266285 relates to a field effect transistor comprising a compound represented by a formula
as a semiconductor material, wherein X1 and X2 each independently denote an oxygen atom, a sulfur atom, or a selenium atom, and R1; R2, R3 and R4 each independently denote a hydrogen atom, a substitutable aliphatic hydrocarbon group, or a substitutable aromatic group. The following DPP compound is explicitly disclosed:

PCT/EP2010/053655 relates to polymers comprising one or more (repeating) unit(s) of the formula
wherein Ar1 and Ar1′ are independently of each other are an annulated (aromatic) heterocyclic ring system, containing at least one thiophene ring, which may be optionally substituted by one, or more groups.
PCT/EP2010/054152 comprising a repeating unit of formula
wherein Ar1′ is an annulated (aromatic) heterocyclic ring system, containing at least one thiazole ring, which may be optionally substituted by one, or more groups,
E. Zhou et al., Chem. Mater. 21 (2009) 4055-4061 (Online publication date: 05.08.2009; DOI:10.1021/cm901487f) discloses three kinds of diketopyrrolopyrrole-based donor-acceptor (D-A) type copolymers, poly{9,9-di(2-ethylhexyl)fluorene-2,7-diyl-alt-3,6-dithien-2-yl-2,5-di(2-ethylhexyl)-pyrrolo[3,4-c]pyrrole-1,4-dione-50,500-diyl}(PF-DTDPP), poly{N-(1-decylundecyl)carbazole-2,7-diyl-alt-3,6-dithien-2-yl-2,5-di(2-ethylhexyl)-pyrrolo[3,4-c]pyrrole-1,4-dione-5′,5″-diyl}(PC-DTDPP), and poly{N-[1-(2-ethylhexyl)-3-ethylheptanyl]dithieno[3,2-b:2′,3′-d]pyrrole-3,6-dithien-2-yl-2,5-di(2-ethylhexyl)-pyrrolo[3,4-c]pyrrole-1,4-dione-5′,5″-diyl}(PDTP-DTDPP). By changing the donor segments, the absorption ranges of DTDPP-containing copolymers can be tuned. PF-DTDPP and PC-DTDPP showed absorption bands in the range of 500-700 nm, while PDTP-DTDPP showed broad absorption in the range of 500-1000 nm in the solutions. The power conversion efficiencies (PCE) of the polymer solar cells (PSCs) based on these copolymers and [6,6]-phenyl C61 butyric acid methyl ester (PCBM) were 0.88% (PF-DTDPP), 2.26% (PC-DTDPP), and 1.12% (PDTP-DTDPP), respectively, under the illumination of AM 1.5 (100 mW/cm2).
L. Huo et al., Macromolecules 2009, 42, 6564-6571 (Online publication date: 06.08.2009; DOI: 10.1021/ma9012972) discloses a series of low-bandgap polymers based on a soluble chromophore of 3,6-dithiophen-2-yl-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione (DPP) unit and different electron-rich building blocks copolymerized with DPP unit. Four new DPP-based polymers,
were synthesized.
In order to investigate their photovoltaic properties, polymer solar cell (PSC) devices based on PDPP-DTS, PDPP-F, PDPP-BDT, and PDPP-BDP were fabricated with a structure of ITO/PEDOT:PSS/polymers:PC70BM(1:2,w/w)/Ca/Al under the illumination of AM 1.5G, 100 mW/cm2.
N. Allard et al., Macromolecules 2010, 43, 2328-2333 (Online publication date: 28.01.2010; DOI: 10.1021/ma9025866) discloses the synthesis of poly[2,7-(9,9-di-n-octylgermafluorene)-alt-3,6-bis(thiophen-5-yl)-2,5-dioctylpyrrolo[3,4-]pyrrole-1,4-dione] and poly[2,7-(9,9-di-n-butylgerma-fluorene)-alt-3,6-bis(thiophen-5-yl)-2,5-dioctylpyrrolo[3,4-]pyrrole-1,4-dione], which shows a hole mobility up to 0.04 cm2 (V 3 s)−1 with an Ion/Ioff ratio of 1.0×106. G. Chen et al., Polymer Chemistry 48 (2010) 1669-1675 [DOI: 10.1002/pola.23931] discloses the synthesis of a narrow-bandgap conjugated polymer (PCTDPP) containing alternating cyclopentadithiophene (CT) and diketo-pyrrolo-pyrrole (DPP) units by Suzuki coupling.

This PCTDPP exhibits a low band gap of 1.31 eV and a broad absorption band from 350 to 1000 nm. A bulk heterojunction polymer solar cell incorporating PCTDPP and C70 at a blend ratio of 1:3 exhibited a high short-circuit current of 10.87 mA/cm2 and a power conversion efficiency of 2.27%.
It is the object of the present invention to provide polymers, which show high efficiency of energy conversion, excellent field-effect mobility, good on/off current ratios and/or excellent stability, when used in organic field effect transistors, organic photovoltaics (solar cells) and photodiodes.